JP2012124305A - Semiconductor module - Google Patents

Abstract

A semiconductor module capable of preventing functional failure of a photoelectric conversion unit due to heat generated from a semiconductor chip is provided.
A first semiconductor chip 101 in which a photoelectric conversion region 118 is formed, and a region on the first semiconductor chip 101 where the photoelectric conversion region 118 is not formed, are electrically connected to the first semiconductor chip 101. Package of the second semiconductor chip 102, the first semiconductor chip 101, and the second semiconductor chip 102 connected together, and at least a region facing the photoelectric conversion region 118 formed of a light-transmitting material 103, and a heat conductive member 109 that thermally couples the second semiconductor chip 102 and the package 103.
[Selection] Figure 1

Description

  The present invention relates to a semiconductor module in which a semiconductor chip is accommodated in a package.

  Conventionally, as an example of a semiconductor module, there is one in which an optical semiconductor element that is a solid-state imaging element is housed in a package together with a semiconductor element that drives a photoelectric conversion unit formed in the optical semiconductor element (for example, Patent Document 1).

FIG. 8 is a cross-sectional view showing the configuration of the semiconductor module described in Patent Document 1. As shown in FIG.
The semiconductor module shown in FIG. 8 has a structure in which a semiconductor element 93, a heat conductive plate 98, and an optical semiconductor element 94 are stacked in order in a concave package 92. The optical semiconductor element 94 and the semiconductor element 93 are electrically connected to a conductor 91 for connecting to an external circuit by wires 95A and 95B, respectively. A light transmissive lid 96 made of a light transmissive material is fixed to the upper end of the package 92 with an adhesive 97. The light that has entered the semiconductor module passes through the light-transmitting lid 96 and enters the photoelectric conversion unit of the optical semiconductor element 94.

  As described above, by mounting the optical semiconductor element 94 and the semiconductor element 93 in the package 92 in a stacked state, the mounting area can be reduced. In addition, since these semiconductor elements are accommodated in one package 92, for example, in a digital still camera manufacturer, a work load when a semiconductor module is incorporated is reduced.

JP 2007-194441 A

  However, according to the configuration of Patent Document 1, since the optical semiconductor element 94 is placed on the upper surface of the heat conductive plate 98, the heat conductive plate 98 is not accurately formed. There is a possibility that 94 is not horizontal with respect to the bottom of the package 92 but is inclined. Here, when a semiconductor module is incorporated into a digital still camera or the like, the lens of the digital still camera is aligned with respect to the package 92. When the optical semiconductor element 94 and the bottom of the package 92 are not horizontal, the optical semiconductor element 94 is not perpendicular to the optical axis of the lens, and the distance between the photoelectric conversion unit and the lens does not match the focal length. As a result, there arises a problem of image quality deterioration such as an image being distorted or blurred.

Therefore, a configuration in which a semiconductor element (hereinafter referred to as a second semiconductor chip) electrically connected to the photoelectric conversion unit is disposed on an optical semiconductor element (hereinafter referred to as a first semiconductor chip). Can be considered. At this time, in order to prevent the second semiconductor chip from blocking the optical path between the light transmissive lid and the region where the photoelectric conversion portion of the first semiconductor chip is formed, the second semiconductor chip is Therefore, it is necessary to arrange the photoelectric conversion unit on the first semiconductor chip outside the region where the photoelectric conversion unit is formed. Furthermore, in order to reduce the size of the semiconductor module, it is necessary to dispose the second semiconductor chip in the vicinity of the region where the photoelectric conversion unit is formed on the first semiconductor chip.

  However, when the above configuration is adopted, there is a possibility that a functional failure may occur in the photoelectric conversion unit due to heat generated from the second semiconductor chip. Examples of functional failures due to heat generation include the following. In a solid-state imaging device, it is necessary to subtract a noise component due to dark current from a video signal in order to make the black level of the video signal constant. The dark current is caused by the thermal noise of the semiconductor that constitutes the photoelectric conversion unit, and when the temperature distribution occurs in the region where the photoelectric conversion unit is formed by the heat generated from the second semiconductor chip, the region There will be a difference in the amount of dark current generated. Since the noise component due to dark current is uniformly subtracted from the video signal in the entire area where the photoelectric conversion unit is formed, if there is a difference in the amount of dark current generated in the area, the amount of noise component that should be subtracted will be reduced. It will not be deducted. As a result, the problem that the image quality deteriorates occurs.

  In view of the above-described problems, the present invention can prevent functional failure of the photoelectric conversion unit due to heat generated from the second semiconductor chip even when the configuration in which the second semiconductor chip is disposed on the first semiconductor chip is employed. An object is to provide a semiconductor module.

  In order to solve the above problems, a semiconductor module according to the present invention includes a first semiconductor chip in which a photoelectric conversion unit is formed, and a region on the first semiconductor chip in which the photoelectric conversion unit is not formed. A second semiconductor chip provided and electrically connected to the first semiconductor chip; and the first and second semiconductor chips are accommodated, and at least a region facing the photoelectric conversion unit is translucent A package made of a material, and a heat conductive member that thermally connects the second semiconductor chip and the package are provided.

  According to the semiconductor module having the above configuration, since the heat conductive member that thermally couples the second semiconductor chip and the package is provided, heat generated from the second semiconductor chip is transferred to the package via the heat conductive member. It is possible to dissipate heat. By setting it as such a structure, it can suppress that the heat | fever generate | occur | produced with the 2nd semiconductor chip moves to the photoelectric conversion part side.

  Therefore, even when the configuration in which the second semiconductor chip is arranged on the first semiconductor chip is adopted, a semiconductor module capable of preventing functional failure of the photoelectric conversion unit due to heat generated from the second semiconductor chip can be provided. .

The heat conductive member may be non-translucent, and the heat conductive member may cover the entire second semiconductor chip in a top view.
Furthermore, when viewed from the top, an opening is provided in a region of the heat conducting member that faces the photoelectric conversion unit, and a peripheral part of the heat conductive member is in contact with an inner wall surface of the package over the entire periphery of the peripheral part. It is good.

  When the second semiconductor chip includes a circuit that handles an analog electrical image signal, when the second semiconductor chip is irradiated with light in a specific wavelength range, photoelectric conversion is performed on the semiconductor that forms the circuit. May cause false signals. However, according to the above configuration, since the non-translucent heat conducting member is provided so as to cover the entire second semiconductor chip, it is possible to prevent generation of a false signal.

Further, the heat conducting member may be made of a metal material.
By using a metal material as the heat conductive member, a heat conductive member having high conductivity and non-light-transmitting property can be configured.

Further, the heat conducting member may be subjected to antireflection treatment on the upper surface of the heat conducting member.
In this way, when there is a space between the heat conduction member and the ceiling of the package, incident light is reflected between the upper surface of the heat conduction member and the lower surface of the ceiling surface of the package. It is possible to prevent the reflected light from entering the photoelectric conversion unit.

  The semiconductor module according to the present invention is provided in a first semiconductor chip in which a photoelectric conversion unit is formed, and a region on the first semiconductor chip in which the photoelectric conversion unit is not formed, and the first semiconductor chip A second semiconductor chip electrically connected to the first and second semiconductor chips, and a package in which at least a region facing the photoelectric conversion unit is formed of a light-transmitting material. The second semiconductor chip is in contact with the package, and a region of the package that is in contact with the second semiconductor chip is made of a material having a higher thermal conductivity than the gas contained in the package. It may be configured.

  According to the semiconductor module having the above configuration, since the second semiconductor chip is provided so as to be in contact with the package, the heat generated from the second semiconductor chip can be radiated to the package. Therefore, it is possible to suppress the heat generated in the second semiconductor chip from moving to the photoelectric conversion unit side.

  A through hole corresponding to the second semiconductor chip is further provided in the ceiling portion of the package, and the second semiconductor chip is inserted into the through hole, whereby an inner wall surface of the through hole is formed. May be in contact with the side surface of the second semiconductor chip.

Furthermore, the lower surface of the ceiling portion of the package may be in contact with the upper surface of the second semiconductor chip.
With this configuration, it is possible to reduce the thickness of the semiconductor module.

The region in contact with the second semiconductor chip in the ceiling of the package may be non-translucent.
According to the above configuration, when the second semiconductor chip includes a circuit that handles an analog electrical image signal, a false signal is generated due to photoelectric conversion performed by the semiconductor that configures the circuit. Can be prevented.

It is a figure showing the whole semiconductor module 100 composition concerning a 1st embodiment. It is a block diagram which shows the specific example of the circuit formed in the semiconductor chip. It is sectional drawing which shows the modification of the joining method of a heat conductive member and a package. (A) It is sectional drawing which shows the whole structure of the semiconductor module 100G which concerns on the modification of 1st Embodiment, (b) It is sectional drawing which shows the whole structure of the semiconductor module 100H which concerns on the modification. (A) A cross-sectional view showing an overall configuration of a semiconductor module 200 according to the second embodiment, (b) a cross-sectional view showing an overall configuration of a semiconductor module 200A according to a modification of the second embodiment, and (c). It is sectional drawing which shows the whole structure of the semiconductor module 200B which concerns on the modification. (A) Sectional drawing which shows the whole structure of semiconductor module 200C which concerns on the modification of 2nd Embodiment, (b) It is sectional drawing which shows the whole structure of semiconductor module 200D which concerns on the modification. (A) It is sectional drawing which shows the whole structure of the semiconductor module 300 which concerns on 3rd Embodiment, (b) It is sectional drawing which shows the whole structure of 300 A of semiconductor modules concerning the modification of 3rd Embodiment. It is a schematic cross section which shows the structure of the conventional semiconductor module.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.
[First Embodiment]
The overall configuration of the semiconductor module 100 according to the first embodiment will be described with reference to FIGS.

  1A is a perspective view showing the entire structure of the semiconductor module 100, and FIG. 1B is a cross-sectional view taken along the line AA (XZ cross-sectional view) shown in FIG. c) is a cross-sectional view (XY cross-sectional view) taken along line B-B shown in FIG.

The semiconductor module 100 includes a first semiconductor chip 101, a second semiconductor chip 102, a package 103, and a heat conduction member 109 as main components.
<package>
The package 103 accommodates the first semiconductor chip 101 and the second semiconductor chip 102 therein, and a region facing the photoelectric conversion portion is formed of a light-transmitting material. Specifically, as shown in FIGS. 1A and 1B, a package 103 includes a ceramic substrate 105, a ceramic side wall 106, and a translucent cover made of a translucent material. 104. For example, an adhesive or the like can be used for fixing between the side wall portion 106 and the translucent cover 104.

  The translucent cover 104 has a flat plate shape and is made of a translucent resin or translucent glass. The translucent cover 104 is fixed to the side wall portion 106 of the package 103 with an adhesive or the like so as to close the opening 112 defined by the package 103.

  As shown in FIGS. 1B and 1C, a plurality of electrode pads 110 are provided inside the package 103. The substrate unit 105 is provided with a plurality of external lead wires 111. A part of the external lead wire 111 is embedded in the substrate unit 105, and the other part protrudes outside the substrate unit 105. . The electrode pads 110 and the external lead wires 111 are respectively connected to wirings embedded in the substrate part 105. The first semiconductor chip 101 is disposed on the upper surface of the substrate unit 105, and the second semiconductor chip 102 is disposed on the upper surface of the first semiconductor chip 101.

<First semiconductor chip, second semiconductor chip>
(Appearance configuration)
The first semiconductor chip 101 functions as an image sensor. The first semiconductor chip 101 includes a silicon substrate 114, a lens layer 115 provided on the silicon substrate 114, and a plurality of electrode pads 116 and 117. In the region 118 in the silicon substrate 114, a plurality of photoelectric conversion portions that receive incident light and perform photoelectric conversion are formed in a matrix. Hereinafter, this region 118 is referred to as a photoelectric conversion region 118. The lens layer 115 is a layer made of a microlens provided for each photoelectric conversion unit of the photoelectric conversion region 118, and guides light incident in the semiconductor module 100 to the photoelectric conversion region 118. For easy understanding, the size of the photoelectric conversion region 118 and the lens layer 115 is exaggerated in FIG. Note that the first semiconductor chip 101 and the substrate unit 105 are bonded by, for example, a metal paste or the like.

  Further, as shown in FIG. 1B, the first semiconductor chip 101 is subjected to photoelectric conversion so that light that has passed through the translucent cover 104 enters the photoelectric conversion region 118 of the first semiconductor chip 101. The region 118 and the translucent cover 104 are disposed so as to face each other.

As shown in FIG. 1B, the electrode pads 116 are bonded to the corresponding electrode pads 110 of the package 103 by wires 119.
The second semiconductor chip 102 includes, for example, a drive circuit that drives a photoelectric conversion unit formed in the first semiconductor chip 101, and an AFE that converts an analog electrical image signal from the first semiconductor chip 101 into a digital signal. (Analog Front End) An integrated circuit chip including a circuit and the like. A plurality of bumps 121 are disposed at the lower end of the second semiconductor chip 102, and the corresponding electrode pads 117 of the first semiconductor chip 101 and the second semiconductor chip 102 are connected via the bumps 121. It is flip-chip bonded so as to be connected. A gap between the second semiconductor chip 102 and the silicon substrate 114 is filled with an underfill material 122 that seals the integrated circuit of the second semiconductor chip 102. The underfill material 122 is used as an adhesive strength enhancer, and as the material, for example, a liquid epoxy resin, a resin sheet, ACF, or the like can be used.

(Circuit configuration)
FIG. 2 is a schematic block diagram showing a specific example of the configuration of a circuit formed in the semiconductor chips 101 and 102. As shown in FIG.

  The first semiconductor chip 101 includes a plurality of photoelectric conversion units 123 arranged in a matrix, a vertical transfer unit 124 provided corresponding to each column of the photoelectric conversion units 123, a horizontal transfer unit 125, and an output circuit Part 126.

  Each photoelectric conversion unit 123 photoelectrically converts incident light to generate a signal charge. The vertical transfer unit 124 reads the signal charge generated by each photoelectric conversion unit 123 and transfers it to the horizontal transfer unit 125 side in the column direction. The horizontal transfer unit 125 transfers the transferred signal charges to the output circuit unit 126 side in the row direction. The output circuit unit 126 converts the transferred signal charge into an electric signal and outputs it to the second semiconductor chip 102.

The integrated circuit of the second semiconductor chip 102 includes a drive circuit 127, an AFE circuit 128, and a TG (timing generator) 129.
The drive circuit 127 generates a drive pulse based on the timing signal generated by the TG 129 in order to drive the photoelectric conversion unit 123 formed in the first semiconductor chip 101, and the generated drive pulse is output to the first semiconductor chip. 101. Here, “driving the photoelectric conversion unit 123 formed on the first semiconductor chip 101” means that the signal charge read out from the signal charge generated by the photoelectric conversion unit 123 is transferred vertically and horizontally. This means that driving is performed so that a series of operations from the transfer to output by the output circuit unit 126 is performed. Accordingly, the drive pulses generated in the drive circuit 127 include drive pulses for driving the vertical transfer unit 124, the horizontal transfer unit 125, and the output circuit unit 126, respectively.

  The AFE circuit 128 performs correlated double sampling (CDS: Correlated Double Sampling) and automatic gain adjustment (AGC: Auto) on the analog image electrical signal output from the output circuit unit 126 based on the timing signal generated by the TG 129. After gain control, it is converted into a digital signal (ADC: Analog Digital Converter).

<Heat conduction member>
As shown in FIGS. 1B and 1C, both the second semiconductor chip 102 and the package 103 are thermally coupled to the region other than the region facing the photoelectric conversion region 118 in the package 103. A heat conducting member 109 is provided. The heat conduction member 109 functions to release heat generated from the second semiconductor chip 102 to the package 103.

  The heat conducting member 109 is made of a material having a higher thermal conductivity than the gas contained in the package 103. Examples of such a material include metal materials such as aluminum, copper, and stainless steel, epoxy resin, acrylic resin, Examples thereof include a resin material having high thermal conductivity such as a silicone resin, and a thermal conductive sheet formed by forming these resin materials into a cloth shape. In addition, when the above-described resin material is used for the heat conducting member 109, it is desirable to mix a heat conductive filler such as zinc oxide, titanium oxide, silver, carbon, ceramics or the like.

  In the above description, it is assumed that the heat conductive member 109 is made of a material having a higher thermal conductivity than the gas contained in the package 103. More preferably, the material has a higher thermal conductivity than the first semiconductor chip 101. It is better to be composed of. When the heat conducting member 109 is made of a material having a higher thermal conductivity than that of the first semiconductor chip 101, the heat radiation of the second semiconductor chip 102 is transferred to the package 103 via the first semiconductor chip 101. The route to the package 103 through the heat conducting member 109 is more dominant than the route to reach. Accordingly, heat transfer to the first semiconductor chip 101 is reduced, and the first semiconductor chip 101 can perform more stable operation.

  By providing the heat conduction member 109 that thermally couples the second semiconductor chip 102 and the package 103, it is possible to efficiently dissipate heat generated from the second semiconductor chip 102 toward the package 103. It becomes. With such a configuration, the functional failure of the photoelectric conversion region 118 due to heat generated from the second semiconductor chip 102 as described above can be prevented.

  In view of miniaturization of the semiconductor module 100, it is desirable that the distance between the photoelectric conversion region 118 and the second semiconductor chip 102 is short. In this case, since the photoelectric conversion region 118 is more easily affected by the heat from the second semiconductor chip 102, it is more important to dissipate the heat generated by the second semiconductor chip 102 toward the package 103.

  Furthermore, the heat generated from the second semiconductor chip 102 is radiated to the package 103 side via the heat conducting member 109, thereby preventing the temperature of the second semiconductor chip 102 from exceeding its own guaranteed operating temperature. be able to. Therefore, the second semiconductor chip 102 can perform a more stable operation.

  As shown in FIG. 1B, the heat conducting member 109 is thermally connected to the package 103 by placing its end on a step 107 provided on the side wall 106. By doing in this way, position alignment of the heat conductive member 109 can be performed easily. In order to further improve the adhesion between the step 107 and the heat conducting member 109, both can be fixed with an adhesive.

  In addition, since the heat conducting member 109 has a flat plate shape, even if the height of the upper surface of the second semiconductor chip 102 is different from the height of the upper surface of the step 107, the heat conducting member 109 is bent. Thus, the second semiconductor chip 102 and the step 107 can be reliably connected.

  Further, when there is a space between the heat conducting member 109 and the translucent cover 104 as in the semiconductor module 100 shown in FIG. 1B, antireflection treatment is applied to the upper surface of the heat conducting member 109. It is desirable to keep it. By doing so, the incident light is reflected between the lower surface of the translucent cover 104 and the upper surface of the heat conducting member 109, thereby preventing the reflected light from entering the photoelectric conversion region 118. it can. Examples of the antireflection treatment applied to the upper surface of the heat conductive member 109 include a chrome plating treatment, a surface roughening, a matte treatment, and an antireflection thin film coating treatment.

<Summary>
In the semiconductor module 100 configured as described above, the heat conducting member 109 that thermally couples the second semiconductor chip 102 and the package 103 is provided. With such a configuration, functional failure of the photoelectric conversion region 118 due to heat generated from the second semiconductor chip 102 can be prevented, and as a result, deterioration in image quality can be suppressed. Furthermore, by letting the heat generated from the second semiconductor chip 102 escape to the package 103, it is possible to suppress the second semiconductor chip 102 from exceeding its guaranteed operating temperature.

  Furthermore, since the second semiconductor chip 102 is disposed on the first semiconductor chip 101, the second semiconductor chip 102 and the first semiconductor chip 101 are arranged side by side as much as the two chips overlap. The package 103 can be reduced in size compared with the case where it is arranged. As a result, the semiconductor module itself can be reduced in size.

  In addition, since the first semiconductor chip 101 as the image sensor and the second semiconductor chip 102 on which the drive circuit 127 and the AFE circuit 128 are formed are accommodated in the package 103, for example, the digital still camera has a semiconductor. When the module 100 is incorporated, it is not necessary to separately incorporate a semiconductor chip on which the drive circuit 127 and the AFE circuit 128 are formed, and accordingly, the assembling work load of the digital still camera can be reduced.

  In the present embodiment, since the first semiconductor chip 101 is placed on the substrate part 105 formed with high accuracy, the first semiconductor chip 101 and the package 103 can be accurately arranged in parallel. . Therefore, when the semiconductor module 100 is incorporated in a digital still camera or the like, the photoelectric conversion region 118 can be accurately arranged perpendicular to the optical axis of a lens of the digital still camera or the like. As a result, image quality deterioration due to image distortion, blurring, and the like due to the distance between the photoelectric conversion region 118 and the lens not matching the focal length can be suppressed. Here, “parallel” means not only completely parallel but also designed so as to be parallel, and includes those deviated from design values due to manufacturing errors or the like.

  Further, according to the configuration shown in FIG. 8, since the signal output from the optical semiconductor element 94 is transmitted to the semiconductor element 93 via the two wires 95A and 95B, the output signal is transmitted at high speed. There is also a problem that it cannot be done.

  On the other hand, in the present embodiment, an output signal from the output circuit unit 126 of the first semiconductor chip 101 can be transmitted directly from the electrode pad 117 to the second semiconductor chip 102 via the bump 121. Therefore, high-speed transmission of the output signal can be realized.

[Modification of First Embodiment]
Next, a modification of the first embodiment will be described. Hereinafter, the description of the same configuration as that of the first embodiment will be omitted, and the description will focus on the differences.

FIG. 3 is an XZ sectional view showing a modification of the method for joining the heat conducting member and the package.
In FIG. 3A, the end portion of the heat conducting member 109A is bent, and the bent portion is fixed to the side wall portion 106 with an adhesive or the like. In FIG. 3B, a slit 108 is provided in the side wall portion 106, and the end portion of the heat conducting member 109 </ b> B is fitted in the slit 108. 3 (a) and 3 (b), the thickness in the X direction of the side wall portion is smaller than that of the semiconductor module 100 shown in FIG. 1 because there is no step for placing the heat conducting member on the side wall portion. Can be thinned.

  In FIG. 3C, the heat conductive member 109 </ b> C is bent twice so that the heat conductive member 109 </ b> C is in contact with both the side wall portion 106 and the substrate portion 105. In this case, since the side wall part 106 and the board | substrate part 105 function as a guide at the time of providing the heat conductive member 109C, position alignment of the heat conductive member 109C can be performed easily. Furthermore, by making the heat conductive member 109C contact both the side wall portion 106 and the substrate portion 105, the contact area between the heat conductive member 109C and the package increases, and heat is generated from the second semiconductor chip more efficiently. Can be dissipated to the package side. The heat conducting member does not necessarily need to be in contact with both the side wall portion and the substrate portion, and the heat conducting member 109D may be in contact with only the substrate portion 105 as shown in FIG. Also in the joining method as shown in FIGS. 3C and 3D, the thickness in the X direction of the side wall portion is made as compared with the semiconductor module 100 shown in FIG. 1 as in FIGS. 3A and 3B. Can be thinned.

  Although FIG. 1 and FIGS. 3A to 3D illustrate the case where the heat conducting member is plate-like, the shape of the heat conducting member is not limited to this. As shown in FIG. 3E, by filling the resin material having excellent thermal conductivity as described above so as to be in contact with the second semiconductor chip, the side wall portion 106, and the substrate portion 105, the heat conducting member 109E is formed. It is good also as forming. As shown in FIG. 3F, the heat conducting member 109F may extend to the photoelectric conversion region side within a range not reaching the photoelectric conversion region. By doing in this way, it can suppress more that the heat radiation from a 2nd semiconductor chip flows in into the photoelectric conversion area | region side. Each of the bonding methods shown in FIGS. 3E and 3F has an advantage that it can be easily formed by pouring a resin material into the package.

FIG. 4 is an XY cross-sectional view showing an overall configuration of a semiconductor module according to a modification of the first embodiment. In addition, in FIG. 4, sectional drawing of the state which removed the translucent cover is shown.
In the semiconductor module 100G shown in FIG. 4A, when the heat conducting member 109G covers the entire second semiconductor chip 102, that is, when the semiconductor module 100G is viewed from above, The entire semiconductor chip 102 is provided so as to overlap. In addition, in the semiconductor module 100H shown in FIG. 4B, the heat conducting member 109H is provided so that the peripheral edge portion of the heat conducting member 109H is in contact with the inner wall surface of the side wall portion 106 of the package over the entire circumference of the peripheral edge portion. ing. Note that an opening is provided in a region facing the photoelectric conversion region 118 in the heat conducting member 109H, and is configured such that the incidence of light on the photoelectric conversion region 118 is not hindered. 4A and 4B, the contact area between the heat conducting member and the side wall portion of the package is increased, and heat from the second semiconductor chip is more efficiently transferred to the package side. It is possible to dissipate heat.

  4, as a method for joining the heat conducting member and the package, a step (step 107G in FIG. 4A and step 107H in FIG. 4B) is provided on the side wall as shown in FIG. Although a method of placing the end portion of the heat conducting member on the step 107G (or step 107H) is illustrated, the present invention is not limited to this method, and the joining method shown in each drawing of FIG.

  Further, the heat conducting members 109G and 109H shown in FIG. 4 are further made of a non-translucent material. With such a configuration, it is possible to prevent malfunction due to light incident on the AFE circuit 128 (FIG. 2) included in the second semiconductor chip 102.

  More specifically, when light in a specific wavelength region (for example, visible light wavelength 380 to 780 [nm]) is irradiated to a semiconductor that constitutes a circuit that handles analog image electrical signals in the AFE circuit 128, There is a case where a false signal is generated due to photoelectric conversion in a semiconductor. If such a false signal is added to the analog electrical image signal, the AFE circuit 128 may malfunction. In addition, the generation of such a false signal leads to deterioration of image quality.

  However, in this modification, the heat conducting members 109G and 109H are made of a non-translucent material, so that the above-described malfunctions and image quality degradation problems do not occur. As shown in FIG. 4A, if the heat conducting member 109G is provided so as to cover the entire second semiconductor chip 102 as a minimum, the above effect can be obtained. Furthermore, as shown in FIG. 4B, the second semiconductor chip 102 can be more reliably shielded from light by covering the entire region excluding the photoelectric conversion region 118 with the heat conducting member 109H.

  4B, the illustration of the light-transmitting cover is omitted, but the shape of the light-transmitting cover in this case is the entire side wall portion 106 as in the semiconductor module 100 shown in FIG. It is also possible to have a shape that closes the opening, or a shape that closes only the opening provided in the region facing the photoelectric conversion region 118.

[Second Embodiment]
Next, a second embodiment will be described with reference to FIG. Hereinafter, the description of the same configuration as that of the first embodiment will be omitted, and the description will focus on the differences.

  FIG. 5A is a cross-sectional view showing the overall configuration of the semiconductor module 200 according to the present embodiment. 1 differs from the semiconductor module 100 shown in FIG. 1 in that the second semiconductor chip 202 is provided so as to be in direct contact with the package 203. More specifically, the lower surface 230 of the ceiling portion 209 of the package 203 and the second semiconductor chip 202 are provided. The upper surface of the semiconductor chip 202 is in contact. Further, the ceiling portion 209 in contact with the second semiconductor chip 202 in the package 203 is made of a material having a higher thermal conductivity than the gas contained in the package 203, and this ceiling portion 209 functions as a heat conduction member. . Hereinafter, the ceiling part that functions as a heat conduction member is referred to as a heat conduction member 209. In addition, an opening 212 is formed in a region facing the photoelectric conversion region 218 in the heat conducting member 209, and a translucent cover 204 is provided so as to close the opening 212. The heat conductive member 209 and the translucent cover 204 are fixed by an adhesive 213, and the second semiconductor chip 202 and the heat conductive member 209 are similarly fixed by an adhesive or the like. Note that the side wall portion 206 and the substrate portion 205 constituting the package 203 are made of ceramic as in the first embodiment.

  According to the configuration of the semiconductor module 200, the semiconductor module 200 is thinned by a thickness corresponding to the gap between the heat conducting member 109 and the translucent cover 104 as compared with the semiconductor module 100 shown in FIG. It becomes possible. In addition, since the second semiconductor chip 202 is in direct contact with the package 203, heat from the second semiconductor chip 202 can be efficiently radiated to the package 203 side. Furthermore, since the heat conducting member 209 constitutes the package 203, heat from the second semiconductor chip 202 can be efficiently radiated into the air outside the package 203.

  FIG. 5B is a cross-sectional view showing the overall configuration of a semiconductor module 200A according to a modification of the second embodiment. The difference from the semiconductor module 200 is that the side wall portion 206 </ b> A is formed of the same material as the heat conducting member 209. According to such a configuration, similarly to the semiconductor module 200, the semiconductor module 200A can be thinned, and a material having high thermal conductivity is also applied to the side wall portion 206A. The heat from the semiconductor chip 202 can be radiated more efficiently into the air outside the package.

  Furthermore, the heat conducting member 209 shown in FIGS. 5A and 5B is further made of a non-translucent material. With such a configuration, it is possible to prevent malfunction due to light entering the AFE circuit included in the second semiconductor chip 202. In order to obtain such an effect, it is sufficient that at least a region in contact with the upper surface of the second semiconductor chip on the lower surface of the heat conducting member has a non-light-transmitting property. It is not necessary to have sex.

  FIG. 5C is a cross-sectional view showing an overall configuration of a semiconductor module 200B according to a modification of the second embodiment. A difference from the semiconductor modules 200 and 200A is that a through hole corresponding to the second semiconductor chip 202 is provided in the heat conducting member 209B constituting the ceiling portion of the package, and the second semiconductor chip 202 is placed in the through hole. It is a point that is inserted. As a result, the inner wall surface of the through hole provided in the heat conducting member 209 </ b> B comes into contact with the side surface of the second semiconductor chip 202. By setting it as such a structure, it is possible to make the semiconductor module 200B thin by the thickness of the heat conductive member 209B. Further, when there is a gap between the inner wall surface of the through hole provided in the heat conduction member 209B and the side surface of the second semiconductor chip 202, the gap is filled with grease, an adhesive, etc. The adhesion between the member 209B and the second semiconductor chip 202 is improved, and heat can be radiated more efficiently.

  The semiconductor module 200B has a configuration in which the upper surface of the second semiconductor chip 202 is exposed from the heat conducting member 209B. Therefore, it is effective when the second semiconductor chip 202 does not include a circuit that handles analog image signals such as an AFE circuit.

Although not particularly illustrated, the side wall portion 206B can be formed of the same material as that of the heat conducting member 209B, similarly to the semiconductor module 200A.
In the case of the configuration of the semiconductor module 200 shown in FIG. 5A, in order to arrange the first semiconductor chip 201 and the translucent cover 204 in parallel with high accuracy, the upper surface of the second semiconductor chip 202 is arranged. It is necessary to make the height equal between the two second semiconductor chips. When the height of the upper surface is different between the two second semiconductor chips, the amount of the adhesive used for fixing the second semiconductor chip 202 and the heat conducting member 209 is adjusted to adjust the second semiconductor chip. The height of the upper surface can be made equal between chips. Similar processing can be applied to the semiconductor modules 200A and 200B in FIGS.

  FIG. 6A is a cross-sectional view showing an overall configuration of a semiconductor module 200C according to a modification of the second embodiment. The semiconductor module 200C is a modification of the semiconductor module 200B shown in FIG. A different part from the semiconductor module 200B is that the translucent cover 204C is fitted into the heat conducting member 209C. With this configuration, the semiconductor module can be further reduced in thickness. Further, like the semiconductor module 200D shown in FIG. 6B, the side wall portion 206D can be formed of the same material as the heat conducting member 209D.

  6 (a) and 6 (b), when the translucent cover is fitted into the heat conducting member, the translucent cover can be easily formed by tapering the heat conducting member as shown in part (X). Can be fitted.

  Similar to the semiconductor module 200B shown in FIG. 5C, the semiconductor modules 200C and 200D have a configuration in which the upper surface of the second semiconductor chip is exposed from the heat conducting member. Therefore, the semiconductor modules 200C and 200D are modifications that can be applied when the second semiconductor chip does not include a circuit that handles analog image signals such as an AFE circuit.

[Third Embodiment]
Next, a third embodiment will be described with reference to FIG. Hereinafter, the description of the same configuration as the first and second embodiments will be omitted, and the description will focus on the differences.

  FIG. 7A is a cross-sectional view showing the overall configuration of the semiconductor module 300 according to this embodiment. The difference from the semiconductor module 200 shown in FIG. 5A is that the ceiling portion of the package is made of a single plate-like material having translucency, and as a result, a portion 309 functioning as a heat conducting member and the translucent light The part 304 that functions as a protective cover is made of the same material. Hereinafter, the portion functioning as the heat conducting member is referred to as a heat conducting portion 309, and the portion functioning as a light transmitting cover is referred to as a light transmitting cover portion 304.

  The translucent member 332 serving as the base of the heat conducting unit 309 and the translucent cover unit 304 is made of a translucent material similar to the translucent cover in the first and second embodiments. A portion where the light-shielding sheet 331 made of a non-translucent material is attached to the upper surface of the translucent member 332 becomes the heat conducting unit 309. The light transmissive member 332 in the region facing the photoelectric conversion region 318 is not attached with the light shielding sheet 331, and the portion where the light shielding sheet 331 is not attached becomes the light transmissive cover portion 304.

  Heat generated from the second semiconductor chip 302 is dissipated to the entire package via the translucent member 332. In addition, when the semiconductor module 300 is viewed from above, the light shielding sheet 331 is attached so as to overlap the second semiconductor chip 302, so that light does not enter the second semiconductor chip 302, and as a result, It is possible to prevent the AFE circuit included in the second semiconductor chip 302 from malfunctioning.

  Further, as in the case of the semiconductor module 200 according to the second embodiment, the thickness corresponding to the gap between the heat conducting member 109 and the translucent cover 104 as compared with the semiconductor module 100 shown in FIG. Accordingly, the semiconductor module 300 can be thinned.

  FIG. 7B is a cross-sectional view showing an overall configuration of a semiconductor module 300A according to a modification of the third embodiment. 7A is different from the semiconductor module 300 shown in FIG. 7A in that a heat conductive portion 309A and a translucent cover portion 304A are formed by attaching a light shielding sheet 331A to the lower surface of the translucent member 332. Is a point. Even with such a configuration, the same effect as that of the semiconductor module 300 shown in FIG. 7A can be obtained. Further, it is desirable that the light shielding sheet 331A according to the present modification is made of a material having high thermal conductivity in addition to non-light-transmitting property. By doing so, the second semiconductor chip 302A and the translucent member 332 are thermally connected via the light shielding sheet 331A with high thermal conductivity, so that more efficient heat dissipation can be expected. it can.

  The first to third embodiments and the modification examples have been described above, but the present invention is not limited to these examples. For example, the following modifications can be considered. Hereinafter, although the first embodiment will be mainly described as an example, it is needless to say that other embodiments and modifications can be similarly applied.

[Other variations]
(1) The thickness of the heat conducting member 109 in the Z direction can be appropriately adjusted according to the distance between the translucent cover 104 and the second semiconductor chip 102 and is not particularly limited. However, as thick as possible, the contact area between the heat conducting member 109 and the package 103 can be increased, and heat generated from the second semiconductor chip 102 can be radiated to the package 103 more efficiently. .

  (2) In the first embodiment and the modification, the example in which the heat conductive member 109 is in contact with the side wall portion 106 or the substrate portion 105 of the package 103 has been described, but the present invention is not limited to this, and the heat conductive member 109 is a package. 103 may be provided in contact with the translucent cover 104.

  (3) In FIG. 1, the step 107 is provided only in the portion of the side wall 106 where the heat conducting member 109 is placed. However, the entire side wall 106 extending in the Y direction is provided with a step. It is good to be.

  (4) In the semiconductor module 100 shown in FIG. 1, the substrate portion 105 is formed of the same material as the side wall portion 106, but these may be formed of different materials. When the substrate part 105 and the side wall part 106 are formed of the same material, it is not necessary to manufacture these parts separately, so that the manufacturing process can be simplified. On the other hand, when forming with another material, it becomes possible to use the most suitable material for each part. In the latter case, for example, an adhesive or the like can be used for fixing between the substrate part 105 and the side wall part 106.

  (5) In the above embodiment, the example in which the number of the second semiconductor chips arranged on the first semiconductor chip is two has been described, but the number of the second semiconductor chips is not limited to this. The number of second semiconductor chips may be one, or three or more. When three or more second semiconductor chips are mounted, it is possible to obtain the same effect as the above-described embodiment by providing a heat conducting member so as to be in contact with each second semiconductor chip and the package. is there. Further, when the number of second semiconductor chips is one, the area of the photoelectric conversion region formed in the first semiconductor chip can be expanded correspondingly. When the area of the photoelectric conversion region is not expanded, the size of the semiconductor module in the X-axis direction can be reduced.

  (6) Although the second semiconductor chip has been described as having a rectangular shape, the shape is not particularly limited. Furthermore, the connection of the second semiconductor chip to the first semiconductor chip is not limited to flip chip bonding using, for example, a bump formed of gold, and other bonding methods such as solder bonding can be employed. .

  (7) In the above embodiment, the semiconductor module provided with the image sensor has been described. However, the present invention is not limited to this. For example, the configuration of the present invention can also be applied to a semiconductor module including a light receiving element such as an optical pickup other than an image sensor, and a light emitting element such as an LED element or a semiconductor laser element. A semiconductor module including a light emitting element will be specifically described as an example. A semiconductor chip in which a light emitting element is formed is a first semiconductor chip, and a semiconductor chip in which a driving circuit for driving the light emitting element is formed is a second semiconductor. Each corresponds to a chip.

  (8) In the first embodiment, the configuration in which the integrated circuit formed in the second semiconductor chip includes the drive circuit, the AFE circuit, and the TG is shown, but the present invention is not limited to this. For example, only a driving circuit may be formed on a semiconductor chip, or only an AFE circuit may be formed. Conversely, circuits other than those described above can also be included.

  (9) In FIG. 4, FIG. 5 (a), (b), it demonstrated on the assumption that the AFE circuit was contained in the 2nd semiconductor chip. When the second semiconductor chip does not include a circuit for handling an analog image signal such as an AFE circuit, it is not necessary to make the heat conducting member non-translucent.

(10) In the above-described embodiment and the like, the configuration in which the side wall portion of the package is made of ceramic is shown, but other than this, for example, it may be formed of resin or the like.
(11) In the above-described embodiments and the like, the configuration in which the first semiconductor chip is wire bonded to the substrate portion has been described. However, the present invention is not limited to this, and for example, a bonding method such as flip chip bonding or solder bonding is adopted. You can also.

  (12) In the above-described embodiments and the like, the example in which the external lead wire is disposed on the side surface of the package has been described. However, the present invention is not limited to this. The shape of the external lead wire is not particularly limited.

  (13) The present invention is not limited to the above-described embodiments and modifications, and various modifications may be made within the scope conceived by those skilled in the art without departing from the spirit of the present invention. Configuration can take.

  The present invention can be suitably used, for example, for an optical semiconductor module that is required to be downsized.

100, 100A, 100B, 100C, 100D, 100E, 100F, 100G, 100H, 200, 200A, 200B, 200C, 200D, 300, 300A Semiconductor module 101, 201 First semiconductor chip 102, 102A, 102G, 102H, 202 302, second semiconductor chip 103, 203, 203A, package base 104, 204, 204A, translucent cover 105, 205 substrate 106, 206, 206A, 206B, 206D side wall 107, 107G, 107H side wall step 108 Slit 109, 109A, 109B, 109C, 109D, 109E, 109F, 109G, 109H, 209, 209B, 209C, 209D Thermal conductive member 110 Electrode pad 111 External lead wire 112, 21 , Opening 114 silicon substrate 115 lens layer 116, 117 electrode pad 118, 218, 318 photoelectric conversion region 119 wire 121 bump 122 underfill material 123 photoelectric conversion unit 124 vertical transfer unit 125 horizontal transfer unit 126 output circuit unit 127 drive circuit 128 AFE Circuit 129 TG
213 Adhesive 230 Lower surface of ceiling part 309, 309A Thermal conduction part 304, 304A Translucent cover part 331, 331A Light shielding sheet 332 Translucent member 91 Conductor 92 Package 92A Package recess 93 Semiconductor element 94 Optical semiconductor element 95A, 95B Wire 96 Light-transmitting lid 97 Adhesive 98 Thermally conductive plate

Claims (9)

A first semiconductor chip on which a photoelectric conversion unit is formed;
A second semiconductor chip provided in a region where the photoelectric conversion unit is not formed on the first semiconductor chip and electrically connected to the first semiconductor chip;
A package in which the first and second semiconductor chips are accommodated and at least a region facing the photoelectric conversion unit is formed of a light-transmitting material;
A semiconductor module comprising: a heat conducting member that thermally connects the second semiconductor chip and the package. The heat conducting member has non-translucency,
The semiconductor module according to claim 1, wherein the heat conducting member covers the entire second semiconductor chip in a top view. When viewed from above, an opening is provided in a region of the heat conducting member facing the photoelectric conversion unit, and a peripheral part of the heat conducting member is in contact with an inner wall surface of the package over the entire periphery of the peripheral part. The semiconductor module according to claim 2. The semiconductor module according to claim 2, wherein the heat conducting member is made of a metal material. The semiconductor module according to claim 1, wherein the heat conducting member is subjected to antireflection treatment on an upper surface of the heat conducting member. A first semiconductor chip on which a photoelectric conversion unit is formed;
A second semiconductor chip provided in a region where the photoelectric conversion unit is not formed on the first semiconductor chip and electrically connected to the first semiconductor chip;
A package in which the first and second semiconductor chips are accommodated and at least a region facing the photoelectric conversion unit is formed of a translucent material;
The semiconductor module, wherein the second semiconductor chip is provided in contact with the package. The ceiling of the package is further provided with a through hole corresponding to the second semiconductor chip,
The semiconductor according to claim 6, wherein an inner wall surface of the through hole is in contact with a side surface of the second semiconductor chip by inserting the second semiconductor chip into the through hole. module. The semiconductor module according to claim 6, wherein a lower surface of a ceiling portion of the package is in contact with an upper surface of the second semiconductor chip. The semiconductor module according to claim 8, wherein a region in contact with the second semiconductor chip in the ceiling portion of the package has non-light-transmitting properties.

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